Mortising-chisel



(No Model.)`

Gr. R. VALENTINE.

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NiTnD STATES PATENT ertoe.

'GEORGE R. VALENTINE, OF NEW BEDFORD, MASSACHUSETTS.

MORTISING-CHISEL.

SPECIFICATION forming part of Letters Patent No. 254,733, dated March'7, 1882-I Application liled December 10, 1880. (No modell) To all whomit may concern:

Be it known that I, GEORGE R. VALENTINE, of New Bedford, in the countyof Bristol, State of Massachusetts, have invented certain new and usefulImprovements in Mortisi ng-Chisels 5 and I do hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, making a part of thisspecification, in Which- Figure l is a perspective view of my chiselfrom the front. Fig. 2 is a like view of the same from the rear. y Fig.3 is a central longitudinal section; and Figs. 4 and 5 arecross-sections upon lines .fr and z z, respectively, of Fig. 3.

Letters of like name and kind refer to like parts in each of thefigures. v

The design of my invention is to cause the removal of chips from amortise during the operation of cutting the same; and to this end itconsists in a mortising-chisel provided withinits back withalongitudinal groove which has its sides or flanks serrated to formhorizontal cut-ters or teeth, substantially as and for the purposehereinafter specified.

In the annexed drawings, A represents a mortising-chisel intended foruse in cutting a right-angled mortise, the front side of said chiselbeing straight and plainT its lower end having the usual cutting-point,c, and its upper end being provided with a shank, c.

Within the back of the chisel is formed a longitudinal groove, a2, whichhas preferably a V-shape in horizontal section, and terminates at ornear the point a. The sides of said groove a2 are provided at" regularintervals with serrations or teeth c3,which extend horizontally acrossthe same and rake upward, so

that when said chisel is moved in such direc-V tion they will engagewith and carry upward 4o the chips which have been formed by the downward movement of said chisel.

The edges a4 of the chisel A, formed by the intersection of its groovedback, are preferably made to operate as cutting-edges, being sharphorizontally, and divided vertically into a number of saw-shaped teethby the ends of the serrations a3.

As thus constructed the chisel is used in the ordinary manner, its pointc and cutting- 5o edges t4 operating to form the end and sides of themortise downward stroke, while upon the upward stroke the teeth orserrations a3 engage with and carry in the same direction the chipsformed by said chisel. y

In consequence of the form of the groove a2 the chips formed by thedownward movement of the chisel A are forced from each side of themortise inward and rearward, and relieve said chisel from the pressurewhich usually causes chisels to become wedged when iirstcansed tooperate within a mortise.

Having thus fully7 set forth the nature and merits ot' my invention,what I claim as new 1s- A mortising-chisel provided within its back withalongitudinal groove, which has its sides or Hanks serrated to formhorizontal cutters or teeth, substantially as and for the purposespecied.

In testimony whereofI hereunto set my hand this 2d day of December,1880.

. GEO. R. VALENTINE.

Witnesses-z R. H. EDDY, E. B. PRATT.

